The invention relates generally to a digital memory device and, in particular, to a current mode simultaneous dual-read/single-write memory device. In the data processing industry there is a definite trend towards utilizing digital circuitry which is small in size and fast in operation. In order to achieve extremely fast operational capability, it is necessary to shorten the circuit paths between the various circuit elements as much as possible and to seek improved operational modes for the circuit elements which permit high-speed, efficient operation. With respect to increasing the operational speed of digital circuitry, it is desirable to have a circuit design which lends itself well to implementation in a high density semiconductor technology. However, as the density of circuitry increases, it becomes imperative that the power consumption of such circuitry be carefully controlled in order that the operational characteristics of the circuitry not be distorted or otherwise inhibited by the generation of excessive heat. With regard to the search for operational modes which permit high-speed operation, the use of current mode logic (CML) has been found to provide a relatively high operational speed. Examples of digital circuits implemented in CML technology may be found in some of the Related Inventions cited above.
Within the architecture of large data processing systems various data storage elements are required. Among the required storage elements are high-speed data storage registers, which registers are utilized for a wide variety of purposes. There is a need for fast, efficient, and reliable data storage registers, which need the present invention serves to fulfill, as will be seen below.